Last week I drove a Tesla P100D in Ludicrous Mode and now I'm obsessed with instant torque. So today I get this idea in my head of attaching an electric motor to the rear axle, a battery in the spare tire well, and (many other parts later) making a plug-in hybrid solely for the additional HP, throttle response, torque, and performance gains. So less like a hybrid and more like the twin engine from the Volvo T8.
I wasted all day researching the feasibility of this and it sounds like after I add the weight of the second system and the cost of integrating it with the current system that it really would not be worth it. Although since I only care about boosting performance and not gas economy and range, I could get away with no brake regen equipment and a smaller battery, this could help. The system would be small and not running at baseline, then when I select Sport mode the rear electric motor kicks in for a few runs before the battery dies.
There are a few wheel hub motors I read about that have 100HP each (Protean Electric), one on each rear wheel. They are light (although unsprung weight). This sounds promising, but nothing to market for individuals
Then I was thinking of finding an old Fusion Energi electric motor and using that to drive the rear wheels. Seems like it should be easier to integrate. But still probably beyond my skill set. There's a place nearby that does EV conversions, but they didn't mention anything about hybrid conversions.
So I just need you guys to tell me I'm off my F'ing rocker and to stop obsessing over this as it is impossible/will never happen/not worth it/no gains, etc. Then maybe I can put the futile research to rest and get some sleep.